Ultrasound assisted one-pot synthesis of 1,2-diaryl azaindoles via Pd/C-Cu catalysis: Identification of potential cytotoxic agents

Ultrasound assisted one-pot and direct access to 1,2-diaryl substituted azaindole derivatives has been achieved via the sequential N-arylation followed by coupling-cyclization under Pd/C-Cu catalysis. The methodology involved initial C[sbnd]N bond forming reaction (step 1) between an appropriate o-bromo substituted amino pyridine and iodoarene followed by C[sbnd]C and C[sbnd]N bond formation (step 2) between the resulting N-aryl substituted intermediate and a terminal alkyne in the same pot. A variety of azaindoles was prepared by using this method. These compounds were assessed for their cytotoxic properties against two different metastatic breast cancer cell lines. Compounds 4i, 4k and 4o showed promising growth inhibition of these cell lines and SIRT1 inhibition in vitro.